throw when missing in usesuspensefragment

[jmvtrinidad]

Can we have an option to throw when there are missing fields.
Right now there is no way to identify if a suspenseFragment has missing fields

[phryneas]

We are adding a dataState property to useSuspenseFragment in 4.0, which is currently in RC state.

That said, unless you pass the returnPartialData: true option, useSuspenseFragment should always suspend until data comes into the cache.
I'm not sure how throwing would make sense here, since that suspending behaviour is pretty much the purpose of useSuspenseFragment in comparison to useFragment.

[jmvtrinidad]

in useFragment there is missing in the response
in code it can be used to show error when there is a value for missing

even we have the dataState, how do we know which is missing?
If the fragment keeps suspending, I need to use useFragment then check the missing field in order to identify the issue.

if dataState is incomplete maybe we can have a configuration if to throw or not from the useSuspenseFragment? or any other way to identify if the fragment is missing some fields from the cache

[phryneas]

I'm sorry, I was previously wrong - useSuspenseFragment doesn't have returnPartialData and also no dataState.

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The point of useSuspenseFragment is that when you use it there is a good chance that data is not there yet, and you want a (partial) component tree to suspend until that data arrives there from a request that's going on somewhere else.

If we were to go with your suggestion to allow useSuspenseFragment to throw an error when data is missing, useSuspenseFragment would never suspend and always throw instead.
It would lose it's core functionality of suspending.

in code it can be used to show error when there is a value for missing

I feel this is the underlying misconception here - you shouldn't use useSuspenseFragment in a code path that should ever need to show an error if data is missing.
In situations where you go for useSuspenseFragment, data should be guaranteed to eventually be present - as requested by another component further up the tree.
If that parent querying component for some reason become unable to guarantee that data, it would be the responsibility of that parent to display an error (and probably unmount the suspended children).